A Dual‐Layer Polyetheretherketone ( PEEK )‐Based Multifunctional Coating: Enhanced Corrosion Resistance, Scale Inhibition, and Antibacterial Performance for Harsh Water Environments

PEEK coatings have been widely applied due to their excellent resistance to high temperatures, wear, and chemical corrosion. However, their application remains challenging in complex aqueous environments prone to scaling and bacterial contamination. To enhance the applicability of PEEK coatings in such conditions, this study successfully fabricated a dual‐layer PEEK‐based multifunctional coating via electrostatic spraying, featuring an anticorrosive inner layer and an antifouling/antibacterial outer layer. The coating exhibits outstanding anticorrosion performance, reducing the corrosion rate of carbon steel in high‐salinity water to 0.00032 mm/a. Furthermore, it demonstrates excellent anti‐scaling properties, maintaining scaling inhibition rates of 67.4%–74.6% for barium sulfate and 71.9%–78.1% for strontium sulfate in scaling‐prone water environments. The coating also achieves an antibacterial rate exceeding 90%. Finally, it shows remarkable durability, with stable performance maintained in complex aqueous environments. Collectively, these results indicate that the developed dual‐layer multifunctional coating holds great potential for industrial applications.